From 1649f3038907174305a9e150c5c6ab92aa9e176a Mon Sep 17 00:00:00 2001
From: RickyRister <42636155+RickyRister@users.noreply.github.com>
Date: Fri, 15 Aug 2025 02:11:39 -0300
Subject: [PATCH] [PictureLoader] Use thread pool instead of creating new
 thread (#6072)

* delete threads

* Run reply processing in thread pool
---
 .../picture_loader/picture_loader_worker.cpp  |  2 +-
 .../picture_loader_worker_work.cpp            | 21 ++++++++++---------
 .../picture_loader_worker_work.h              |  4 ++--
 3 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/cockatrice/src/client/ui/picture_loader/picture_loader_worker.cpp b/cockatrice/src/client/ui/picture_loader/picture_loader_worker.cpp
index 26cf09156..ff3b5fcbb 100644
--- a/cockatrice/src/client/ui/picture_loader/picture_loader_worker.cpp
+++ b/cockatrice/src/client/ui/picture_loader/picture_loader_worker.cpp
@@ -94,7 +94,7 @@ QNetworkReply *PictureLoaderWorker::makeRequest(const QUrl &url, PictureLoaderWo
     QNetworkReply *reply = networkManager->get(req);
 
     // Connect reply handling
-    connect(reply, &QNetworkReply::finished, worker, [reply, worker] { worker->handleNetworkReply(reply); });
+    connect(reply, &QNetworkReply::finished, worker, [reply, worker] { worker->acceptNetworkReply(reply); });
 
     return reply;
 }
diff --git a/cockatrice/src/client/ui/picture_loader/picture_loader_worker_work.cpp b/cockatrice/src/client/ui/picture_loader/picture_loader_worker_work.cpp
index 1e7600a75..f8af2a001 100644
--- a/cockatrice/src/client/ui/picture_loader/picture_loader_worker_work.cpp
+++ b/cockatrice/src/client/ui/picture_loader/picture_loader_worker_work.cpp
@@ -11,6 +11,7 @@
 #include <QNetworkDiskCache>
 #include <QNetworkReply>
 #include <QThread>
+#include <QThreadPool>
 
 // Card back returned by gatherer when card is not found
 static const QStringList MD5_BLACKLIST = {"db0c48db407a907c16ade38de048a441"};
@@ -28,16 +29,7 @@ PictureLoaderWorkerWork::PictureLoaderWorkerWork(const PictureLoaderWorker *work
     // Hook up signals to settings
     connect(&SettingsCache::instance(), SIGNAL(picDownloadChanged()), this, SLOT(picDownloadChanged()));
 
-    pictureLoaderThread = new QThread;
-    moveToThread(pictureLoaderThread);
-
-    connect(pictureLoaderThread, &QThread::started, this, &PictureLoaderWorkerWork::startNextPicDownload);
-
-    // clean up threads once loading finishes
-    connect(this, &QObject::destroyed, pictureLoaderThread, &QThread::quit);
-    connect(pictureLoaderThread, &QThread::finished, pictureLoaderThread, &QObject::deleteLater);
-
-    pictureLoaderThread->start(QThread::LowPriority);
+    startNextPicDownload();
 }
 
 void PictureLoaderWorkerWork::startNextPicDownload()
@@ -78,6 +70,15 @@ void PictureLoaderWorkerWork::picDownloadFailed()
     }
 }
 
+/**
+ * Processes the reply in another thread.
+ * @param reply The finished reply. Takes ownership of the object
+ */
+void PictureLoaderWorkerWork::acceptNetworkReply(QNetworkReply *reply)
+{
+    QThreadPool::globalInstance()->start([this, reply] { handleNetworkReply(reply); });
+}
+
 /**
  *
  * @param reply The reply. Takes ownership of the object
diff --git a/cockatrice/src/client/ui/picture_loader/picture_loader_worker_work.h b/cockatrice/src/client/ui/picture_loader/picture_loader_worker_work.h
index d03160463..87f8e5cb8 100644
--- a/cockatrice/src/client/ui/picture_loader/picture_loader_worker_work.h
+++ b/cockatrice/src/client/ui/picture_loader/picture_loader_worker_work.h
@@ -30,14 +30,14 @@ public:
     PictureToLoad cardToDownload;
 
 public slots:
-    void handleNetworkReply(QNetworkReply *reply);
+    void acceptNetworkReply(QNetworkReply *reply);
 
 private:
-    QThread *pictureLoaderThread;
     bool picDownload;
 
     void startNextPicDownload();
     void picDownloadFailed();
+    void handleNetworkReply(QNetworkReply *reply);
     void handleFailedReply(const QNetworkReply *reply);
     void handleSuccessfulReply(QNetworkReply *reply);
     QImage tryLoadImageFromReply(QNetworkReply *reply);